Plastic bag winding machine

ABSTRACT

A portable machine for winding assorted lengths of materials fed from another machine, such as a plastic bag making machine, into a tight, wrinkle-free roll. The machine comprises an inclined feed ramp having an outer surface positioned so that the material is draped there-against. The material is fed over the top of the ramp down the other side of the ramp through a set of jungle bars and through a speed-controlled nip roll drive assembly to a takeup roll that is driven by a torque motor. The inclined ramp has three sensors spaced therealong and recessed inwardly so as not to obstruct the movement of the material up the inclined ramp. These sensors control the speed of the drive motor for the nip roll assembly as the sensors are either covered or uncovered and determine the speed control reference for the drive motor for the nip roll assembly.

United States Patent 1191 Copp Oct. 29, 1974 PLASTIC BAG WINDING MACHINE Primary ExaminerJhn W. Hucrkert [75] Inventor. Robert M. Copp, Brockton, Mass. Assistant Examiner john M jmions Asslgneei Park-Air n, Brockton, as Attorney, Agent, or Firm-Wolf, Greenfield & Sacks [22] Filed: Apr. 13, 1972 [57] ABSTRACT [21] Appl' 243762 A portable machine for winding assorted lengths of materials fed from another machine, such as a plastic Cl 2/672, bag making machine, into a tight, wrinkle-free roll. 242/7551 The machine comprises an inclined feed ramp having 1365i! B6511 1365b 25/20 an outer surface positioned so that the material is Field 0f Search draped there-against. The material is fed'over the top 2 /753; 242/672, of the ramp down the other side of the ramp through 75-44 a set of jungle bars and through a speed-controlled nip roll drive assembly to a take-up roll that is driven by a References Cited torque motor. The inclined ramp has three sensors UNITED STATES PATENTS spaced therealong and recessed inwardly so as not to 2,214,609 9/1940 Drake 242/7551 x OhShhCt the movement 0f the material the inclined 2,583,674 1/1952 Tobler 242/674 x ramp- These Sensors Control the Speed Of the drive 3,023,430 3 19 2 s h et 1 242 57 X motor for the nip roll assembly as the sensors are ei- 3,109,604 11/1963 Brenner 242/187 X ther covered or uncovered and determine the speed 3,1 11/1963 Wicklund t 242/ X control reference for the drive motor for the nip roll 3,310,250 3/1967 Michiels et al. 242/184 assembly, 3,379,390 4/1968 Eastcott 242/75.44 3,458,151 7/1969 Eastcott 242/7544 4 Claims, 8 Drawing Figures SPEED CONTROL PMENIEB 0m 29 m4 IP QIHH Xom 6528 Emma P AI N umzsum 3" l D E In sum 30? 3 844 463 H DRWE 12 5/ l7 MOTOR FULL SPEED /OOF 52 /9 FORWARD REVERSE 52 (slow) 25 mam l I SPEED REFERENCE A) 29 53 2/ POTENTIOMETER -c O H64 I H67 E PLASTIC BAG WINDING MACHINE BACKGROUND OF THE INVENTION The present invention relates in general to winding machines for winding lengths of relatively thin, lightweight material into a roll. More particularly, the pres ent invention is concerned with a novel machine for winding material into a roll wherein the machine is portable and is provided with speed control means for enabling proper winding of the material regardless of whether the input feed is continuous or intermittent.

There are numerous types of machines for producing lengths of material such as lengths of perforated tearoff plastic bags. Someof these machines operate intermittently and some of them operate continuously. In either case it is necessary to provie a machine for winding these lengths of materials into a roll. Most of the winding machines presently available are rather bulky and expensive. Also, these known machines are generally associated, one with each bag making machine,

and are fixed in position. Thus, it is not possible to readily use one of the winding machines with another feeding machine.

Another disadvantage associated with some machines is that they do not operate effectively when the feeding machine is of the intermittent type. The resultant roll produced by the winding machine may not be tight and therefore difficult to handle. Also, with some machines if the feeding machine is not operating at a relatively constant speed, there may be the necessity for periodically checking the machine to determine if the winding is proceeding too slowly or too rapidly.

OBJECTS OF THE INVENTION Accordingly, one important object of the present invention is to provide an improved machine for winding material into a roll. The machine of the present invention provides a relatively tight, wrinkle-free and uniform width roll.

Another object of the present invention is to provide a winding machine for lengths of material that is portable and may be constructed relatively inexpensively in comparison with known winding machines. With the portable machine of the present invention there may be an additional savings in that one winding machine can be moved to service more than one feeding machine.

A further object of the present invention is to provide a machine for winding lengths of material wherein the machine can be operated unattended regardless of whether the feeding machine is operated intermittently or at varying speeds.

Still another object of the present invention is to provide an improved winding machine for lengths of material including novel speed-control means for readily controlling the take-up speed of the material onto the roll in dependence upon the average integrated operating speed of the feeding machine.

Still a further object of the present invention is to provide a winding machine for lengths of material including an improved nip roll assembly.

Another object of the present invention is to provide a winding machine for lengths of material such as lengths of perforated plastic bags wherein the material fed from the feeding machine is draped against an inclined plate of the winding machine, over the top of the plate and down the other side to a speed-controlled drive means for the material wherein the drive means is speed-controlled in relation to the extent with which the material covers the inclined plate. In a preferred embodiment three spaced sensors are used along the plate to determine the extent of coverage of the material over the length of the inclined ramp.

SUMMARY OF THE INVENTION To accomplish the foregoing and other objects of the present invention the machine generally comprises an inclined feed ramp or plate positioned for receiving the material from the feeding machine along at least a portion of the outer surface of the inclined feed ramp. The outer surface is the surface considered as facing the feeding machine. The machine also includes a drive roll assembly, means for securing the drive roll assembly adjacent the inner surface of the feed ramp and means for rotatably driving the drive roll assembly. In the disclosed embodiment discussed in more detail hereinafter, there are provided two separately operated take-up rolls which are suitably secured for rotation and have separate torque motors coupled thereto for properly tensioning the material intermediate the drive roll assembly and the take-up rolls as the material is being wound.

In accordance with one aspect of the present invention the inclined plate has means defining openings which are preferably three horizontal slits each one of which has a sensor associated therewith. These sensors in the disclosed embodiment are fluidic sensors which are bistable devices that are in a first position when the material is greater than a predetermined distance therefrom and in a second position when the material is less than a predetermined distance therefrom.

When none of the sensors are covered (material not within the predetermined distance of any sensor) the material is obviously being taken-up faster than it is fed from the feeding machine and thus the drive means of the machine is disabled. When the first, uppermost sensor is covered the drive motor is enabled and operates in accordance with a predetermined speed control setting. If this speed control setting is too fast, the uppermost sensor will again be uncovered and the speed control reference changes by some set amount. Eventually, the first sensor remains covered and when the middle sensor also becomes covered the speed reference remains at a constant predetermined value. If the average speed from the feeding machine remains constant, theoretically, the draped material should stay in this position with the two uppermost sensors covered and the lowermost sensor not covered. If the lowermost sensor does become covered, because the winding machine is not operating fast enough for the average speed of the feeding machine, the speed reference is increased and the drive motor is selectively operated at full speed for a short period of time. The speed reference periodically changes until the lower sensor is uncovered, and the machine is operating under the desired condition of the two uppermost sensors covered and the lowest sensor uncovered.

BRIEF DESCRIPTION OF THE DRAWINGS Numerous other objects, features and advantages of the invention should now become apparent upon a reading of the following detailed description taken in conjunction with accompanying drawings in which:

FIG. 1 is a side view of the winding machine of the present invention;

FIG. 2 shows an opposite side view of the winding machine shown in FIG. 1;

FIG. 3 is a back view of the machine shown in FIGS. 1 and 2;

FIG. 4 is an elevational view of the inclined plate shown in FIGS. 1 and 2;

FIG. 5 shows a perspective view of one of the sensor assemblies shown in FIG. 4;

FIG. 6 is a plan view of the sensor holder of FIG. 5 indicating the angle between the received and transmitter sensors;

FIG. 7 is a circuit schematic diagram of the speedcontrol means of the present invention; and

FIG. 8 shows one specific embodiment for the nip roll assembly of the present invention.

DETAILED DESCRIPTION Referring now to the drawings and in particular to FIGS. l-3, there is shown a machine for winding lengths of material which generally comprises a base platform 10 which is preferably constructed of predetermined lengths of rectangular bars of metal interconnected to form the base platform 10, and a pair of inclined members 12 and 14 which are suitably fixed at their lower end, such as by welding, to the base platform 10.

A feeding plate 16, which is shown in more detail in FIG. 4, is secured to the outer surface of members 12 and 14, such as by use of sheet metal screws, and the plate 16 is preferably constructed of a polyethylene plastic and is thereby usable for removing static electricity from the material 18 which is being fed from a feeding machine (not shown) which may be a poly bag making machine.

The machine shown in FIGS. 1-3 is made readily portable with the use of conventional casters 20 which are disposed at or near the four corners defining the base platform 10. These casters 20 may be secured to the platform 10 in a known manner and are preferably of the swivel type to permit easy movement of the winding machine.

An upper set of horizontal bars 22- and 24 extend from the inner surface of members 12 and 14, respectively. The bar 22 has a shaft 26 extending therefrom with a chuck 27 at the end thereof for holding one side of the roll 28 which has the material 18 wound thereabout. The bar 24 has a horizontally movable shaft 30 which is air actuated by lever 32 to force the chuck 34 against core 28 and keep the core 28 tightly between the chucks 27 and 34. Bar 22 also has a tapered tension torque motor 36 attached thereto for rotatably driving the shaft 26 and in turn the core 28 to facilitate the wrapping of the material 18 therearound. FIG. 1 shows a conventional compressed air arrangement for feeding compressed air to the torque motors. A similar arrangement is used to control the moveable chucks.

FIG. 3 also shows a second take-up means 40 disposed below roll 28. Means 40 is secured from lower horizontal bars 42 and 44, and comprises a core 46, supporting chucks 47 and 48, actuating lever 50, and torque motor 52. As indicated in FIG. I the compressed air line 54 is also fed to actuating lever 50 for controlling the chuck 47 in a horizontal direction and to motor 52.

A plurality of jungle bars 60 are spacedly disposed extending between inclined members 12 and 14 and may be suitably secured in recesses in these members. Each of the jungle bars 60 includes a pair of spacers 62 for limiting the horizontal displacement of the material 18 as the material extends up the plate 16, over the top of the uppermost jungle bar 60 and sequentially forward and back of the remaining jungle bars as the material is directed downwardly toward the nip roll assembly 70.

The nip roll assembly is secured at both ends to bars 72 and 74 and is driven by way of drive chain 76 from a speed-controlled drive motor 78. The speed of motor 78 is controlled from speed control box 80.

Nip roll assembly 70 includes a drive roll 82 and an idler roll 84. A specific improved embodiment for a nip roll assembly is shown in more detail and discussed hereinafter with reference to FIG. 8. The idler roll 84 is preferably movable so that the material 18 may be extended between the rolls 82 and 84 to either the take-up core 28 or take-up core 46. Means are provided on the nip roll assembly as discussed hereinafter for securing the nip rolls 82 and 84 in gripping relationship with the material when the machine is ready for winding. A pair of ion bars may also be disposed horizontally between the lowest jungle bar 60 and the nip roll assembly. These ion bars are of conventional design and include a series of trapping apertures for collecting negative charges which are carried away from the material being wound thereby tending to neutralize the charge on the material.

Material delivered from the feeding machine may be delivered intermittently or at a non-constant speed and thus it is possible for the material 18 to assume the position shown in a solid line in FIG. 2, or it is possible for it to assume other positions such as the dotted positions also shown in FIG. 2. In accordance with the present invention there are preferably three sensors associated with the inclined plate 16 for determining the position of the material 18 and the amount of sag therein. The amount of sag is dependent upon the average speed difference between the feed speed and winding speed. FIG. 4 shows an elevational view of the plate 16 and the three sensors S1, S2 and S3. The sensors Sl-S3 are recessed inwardly from the outer surface 16A of the plate 16 and the plate 16 is provided with three recesses 17, 19 and 21. The machine also includes holding rods 23, 25 and 29 which extend horizontally between the members l2 and 14 and have the sensors Sl-S3 slidably mounted therealong. FIG. 5 shows a perspective view of one of the sensor assemblies having a channel 85 therein for fitting over one of the holding rods shown in FIG. 4. The sensors S1, S2 and S3 are approximately equally spaced with the sensors S2 and S3 slightly closer together than sensors S1 and S2. The operation of these sensors is discussed in more detail hereinafter with respect to the speed-control circuit diagram of FIG. 7.

Referring now to FIGS. 5 and 6, there is shown a sensor assembly 86 which comprises a supporting block 88 having channel 85 for fitting over one of the rods 23, 25 or 29, a transmitting sensor 90 and a receiving sensor 92. In a preferred embodiment the sensors are of the fluidic type, have pressure input lines fed thereto, and are of conventionaldesign. These sensors are normally used in an aligned orientation to detect the presence or absence of objects therebetween. However, in

accordance with the present invention these sensors are oriented as specifically shown in FIG. 6 so as to detect the presence of the material 18 when it approaches a predetermined distance. In one embodiment the threshhold distance is 5 inches from the sensor assembly to the material I8.

For different applications the width of the material 18 that is being wound may vary and thus it has been advantageous to provide a movable sensor assembly 86. For this purpose the block 88 is provided with a tightening screw 94. When the screw is loosened the block 88 may be moved horizontally to the desired position and then the screw 94 can be tightened to secure the assembly 86 in its proper position.

FIG. 6 shows a plan view of the block 88 of FIG. 5 with sensors 90 and 92 removed. Block 88 defines two channels 96 and 98 for respectively accommodating sensors 90 and 92. The distance d between the edges of channels 96 and 98 is relatively critical and it has been found that it should be on the order of 5/8 inch. The sensors are also about 5/8 inch at their closest point. The center of sensors 90 and 92 as indicated by the distance b is thus on the order of 1% inches.

It has also been found that the angle A between the sensor 90 and the normal line L and the angle B between the sensor 92 and the normal line M is critical (see FIG. 6). It has been difficult to specifically determine the exact reasons for this criticality. However, it is believed that there are three factors that had to be balanced in determining these two angles. The first factor is the value of the pressure supplied to the sensors which has to be controlled to within a 0.3 p.s.i. working range. The second factor is concerned with the interferometry aspect of the sensors wherein the sensors 90 and 92 have to be directed angularly toward each other to provide signal cancellation but only at ranges from the sensors greater than some predetermined minimum range. The critical angles A and B also depend upon the desired threshhold range. It has been generally found that angle A should be greater than angle B. Angle A should be on the order of 40 and angle B on the order of Referring now to FIG. 7, there is shown a circuit schematic diagram of the speed-control circuitry of the present invention including the drive motor 78, integrator motor I00 which is a bidirectional motor and the three sensors Sl-S3 which are shown schematically as switch contacts 81-53. In the actual machine the output of the sensors shown in FIG. 4 couples to a pneumatically or fluidically operated mechanical switch and it is this switch contact that is shown in FIG. 7.

In FIG. 7 all of the sensor switches Sll-S3 are shown in their non-detecting position and all of the relays are shown in their de-energized position. Also, the power ON-OFF switch 102 is shown in its OFF position. The power to the circuitry of FIG. 7 is provided from a conventional 110 volt AC line. When the power switch 102 is, as shown, power is not coupled to relay K4 and its associated contact K4A, which is in series with drive motor 78, is in its open position. When the power switch 102 is actuated, relay K4 is energized, its latching contact K4B closes maintaining relay K4 energized and the relay contact K4A closes.

In discussing the diagram of FIG. 7 reference is also made to FIGS. 2 and 4. In FIG. 2 the material 18 is shown in a solid line in position W and in three other positions, respectively, referred to as positions X, Y

and Z. In position W none of the sensors S1, S2 or S3 are covered (actuated). In position X sensor S1 is covered, in position Y sensors SI andSZ are covered and in position Z all three of the sensors are covered. The following discussion commences from the point wherein none of the sensors are covered and proceeds through the operation as each of the sensors is covered in sequence.

When the winding machine is initially started the speed reference potentiometer 104 which is associated with drive motor 78 and determines the speed thereof, may be set at a relatively fast speed. as previously determined by integrator motor 100. Thus, when the winding machine is turned on there will be little or no slack in the material 18 and it may assume a position such as position W. In that case switch S1 is open as shown in FIG. 7 relay K1 is de-energized, the associated contact KIA is open and there is no power provided to drive motor 78 even though contact K4A is closed. Thus, the drive motor 78 is turned off and the nip roll assembly remains stationary (non-rotating).

As the material is fed from the feeding machine the sensor Sll is covered and thus relay K1 becomes energized. This causes its associated contact KI to close and the drive motor 78 is operated. Concurrently with the starting of the machine power is also applied by way of contact K38 and switch S2 to the reverse input R of bi-directional integrator motor I00 causing the reference potentiometer 104 to be slowly reset to a slower reference speed. When the switch S1 is covered and the drive motor 78 is operated the speed reference may still be too fast in which case the drive motor is again turned off because switch S1 again opens (relay Kll deenergizes) and the speed reference setting of potentiometer 104 continues to decrease to a slower speed reference. Eventually, sensor SI will become covered and remain covered and thus the material 18 may be in a position such as position X shown in FIG. 2 covering sensor S1 but not covering sensors S2 and S3.

In referring to the material as covering a sensor it is meant that the material has reached the threshhold range of the sensor sufficiently close thereto to cause actuation thereof. If some type of mechanical sensor switch is used in place of the sensors shown, an actual physical contact is necessary.

With the power still being applied by way of contact K38 and switch S2 to the reverse input of motor 100 the speed reference continues to slow down. At some point in time the sensor S2 will be covered as the material will come within sufficient proximity thereto and its contact shown in FIG. 7 opens. When this occurs there is no power provided to either the reverse or the forward inputs of integrator motor 100 and the reference potentiometer I04 remains on a predetermined setting for driving the drive motor 78 at a constant speed associated with this potentiometer setting. Theoretically, if the feeding machine remains at a constant speed the drive motor should continue at the speed determined by the potentiometer 104. However in practice it is possible for the material to be fed more rapidly from the feeding machine in which case the material will go from position Y to position Z wherein the three sensors 81-83 are covered. In that case the associated contact S3 closes, energizing relay K3, causing a position change of contact K3A to drive the motor 78 at full speed, and causing a position change of contact K38 to drive the integrator motor in the opposite direction by way of power applied to the forward input 100F of the motor 100. Thus, the closing of switch S3 causes motor 78 to be driven at full speed temporarily to take up the slack and additionally changes the reference setting of potentiometer 104. If the feeding machine has changed its speed considerably it is possible for sensor S3 to be covered and uncovered a number of times until the reference setting of potentiometer 104 has properly compensated for this change in speed. The final desired operating position is thus position Y wherein sensors S2 and S1 are covered but sensor S3 is not covered.

Referring now to FIG. 8 there is shown an improved embodiment of the nip roll assembly 70. This nip roll assembly includes supporting members 106 and 108 each of which includes a bearing support means for supporting the drive roll 110 and the idler roll 112. The assembly is provided with preferably a pair of handles 114 coupled to a cam means 116 associated therewith for displacing the roll 110 relative to the roll 112 to permit passing of the material 18 therebetween. The members 106 and 108 also have spring biasing means associated therewith for fixing the position of the two rolls 110 and 112 in gripping relationship.

One feature of the present invention is the use of an inclined plate over which the material is fed. The plate can be oriented at many different angles but the best results are obtained when the plate is at an angle on the order of 60 from the horizontal. The angle can be less than 60 but preferably should not be much greater than 60. The use of the inclined plate has eliminated the use of dancer rollers in the machine and has enabled the material to sag and remove wrinkles therefrom.

What is claimed is:

1. Apparatus for controlling the winding of material onto a take-up roll comprising;

an inclined feed plate positioned for receiving said material, fed from one side of said plate, against at least a portion of the outer inclined surface of said plate with said material contacting the top end of said plate and draping downwardly therefrom, means including a drive roll, drive means and drive roll support means disposed on the other side of said plate for feeding said material to the take-up roll,

a pair of sensors including a first sensor and a second sensor spaced above the first sensor and disposed along said inclined surface,

each said sensor capable of sensing when the material is less than a predetermined distance from the sensor in which case the sensor is considered as being covered,

said plate having means for receiving said sensors,

means for establishing a reference speed setting for controlling the speed of operation of said drive means,

a power source,

bidirectional means for changing said speed reference setting, said bidirectional means including forward and reverse inputs selectively coupled to said power source for increasing or decreasing, respectively, said speed reference setting,

means responsive to said first and second sensors being uncovered for coupling said reverse input to said power source to thereby decrease said reference speed setting,

means responsive to said first sensor being uncovered and said second sensor being covered for uncou pling any of said inputs from said power source to thereby maintain said reference speed at a fixed setting, and

means responsive to said first and second sensors being covered for coupling said forward input to said power source to thereby increase said reference speed setting.

2. The apparatus of claim 1 further comprising a third sensor disposed above said second sensor, said plate having means for receiving said third sensor, and means responsive to said third sensor being covered for enabling said drive means, and being uncovered for inhibi'ting operation of said drive means.

3. The apparatus of claim 2 including means for operating the drive means at full speed when said first sensor is covered.

4. The apparatus of claim 3 wherein said means for establishing a reference speed setting includes a potentiometer. 

1. Apparatus for controlling the winding of material onto a take-up roll comprising; an inclined feed plate positioned for receiving said material, fed from one side of said plate, against at least a portion of the outer inclined surface of said plate with said material contacting the top end of said plate and draping downwardly therefrom, means including a drive roll, drive means and drive roll support means disposed on the other side of said plate for feeding said material to the take-up roll, a pair of sensors including a first sensor and a second sensor spaced above the first sensor and disposed along said inclined surface, each said sensor capable of sensing when the material is less than a predetermined distance from the sensor in which case the sensor is considered as being covered, said plate having means for receiving said sensors, means for establishing a reference speed setting for controlling the speed of operation of said drive means, a power source, bidirectional means for changing said speed reference setting, said bidirectional means including forward and reverse inputs selectively coupled to said power source for increasing or decreasing, respectively, said speed reference setting, means responsive to said first and second sensors being uncovered for coupling said reverse input to said power source to thereby decrease said reference speed setting, means responsive to said first sensor being uncovered and said second sensor being covered for uncoupling any of said inputs from said power source to thereby maintain said reference speed at a fixed setting, and means responsive to said first and second sensors being covered for coupling said forward input to said power source to thereby increase said reference speed setting.
 2. The apparatus of claim 1 further comprising a third sensor disposed above said second sensor, said plate having means for receiving said third sensor, and means responsive to said third sensor being covered for enabling said drive means, and being uncovered for inhibiting operation of said drive means.
 3. The apparatus of claim 2 including means for operating the drive means at full speed when said first sensor is covered.
 4. The apparatus of claim 3 wherein said means for establishing a reference speed setting includes a potentiometer. 